小编Dim*_*rio的帖子

我想用UIView动画制作改变UITableViewCell高度的动画(将来用弹簧动画制作).

所以我有:

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *CellIdentifier = @"Cell";
    UITableViewCell *cell = (UITableViewCell*)[tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    if (cell == nil)
    {
        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
        cell.backgroundColor = [UIColor greenColor];
    }
    UILabel *viewLabel = [[UILabel alloc] initWithFrame:CGRectMake(10.0f, 10.0f, [[UIScreen mainScreen] bounds].size.width, 40.0f)];
    viewLabel.text = @"Test";
    viewLabel.backgroundColor = [UIColor clearColor];
    [cell.contentView addSubview:viewLabel];

    return cell;
}

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    [tableView beginUpdates];
    [self animateCell:indexPath andTableView:tableView];
    [tableView endUpdates];
}


- (void)animateCell:(NSIndexPath*)indexPath andTableView:(UITableView*)tableView
{
    [UIView animateWithDuration:1.0f animations: ^ …

在CI有

uint32 value = 39434;
uint8 firstByte = (unsigned char)value;
uint8 secondByte = (unsigned char)(value >> 8);

有没有可能在Swift中实现同样的目标？

尝试在SCNRender对象的每个调用渲染中从MTLTexture创建CVPixelBufferRef：

  CVPixelBufferLockBaseAddress(pixelBuffer!, CVPixelBufferLockFlags(rawValue: 0))
        let bytesPerRow = 4 * Int(textureSizeX)
        let region = MTLRegionMake2D(0, 0, Int(textureSizeX), Int(textureSizeY))

    var tmpBuffer = CVPixelBufferGetBaseAddress(pixelBuffer!);

    offscreenTexture.getBytes(tmpBuffer!, bytesPerRow: bytesPerRow, from: region, mipmapLevel: 0)

    CVPixelBufferUnlockBaseAddress(pixelBuffer!, CVPixelBufferLockFlags(rawValue: 0))

然后转换为UIImage以显示在屏幕上

    let ciImage = CIImage.init(cvPixelBuffer: pixelBuffer!)
    let temporaryContext = CIContext(options: nil)
    let tempImage = temporaryContext.createCGImage(ciImage, from: CGRect(x: 0, y: 0, width: textureSizeX, height: textureSizeY))
    let uiImage = UIImage.init(cgImage: tempImage!)

但是不显示图像